Hours after a tractor plowed into the side of an Amtrak train at a railroad crossing about 70 miles east of Reno, Nev., officials continued to have trouble getting access to smoldering rail cars to discover if they could locate additional survivors -- or victims, beyond at least two known dead.

The impact at the crossing on U.S. 95 created a massive burst of flames and smoke, sent passengers fleeing the train and caused dozens of injuries.

"Unfortunately, with the fires in the train still, and the flare ups, we have not gained access into the train yet to make sure that we got everybody out," Nevada Highway Patrol Trooper Dan Lopez told ABC News.

The truck driver and an unidentified train occupant are known to have died in the crash, Lopez said, though the toll could go up as officials gain more access to the wreck.

Eighteen to 20 people were transported to hospitals in buses for treatment, Lopez said.

Local media reported "dozens" of people were hurt, including some carried in helicopters to trauma centers.

An Amtrak spokesman told the AP that the injuries were not life threatening, though he did not offer other details.

The preliminary investigation and witness statements indicate the truck driver was going northbound on U.S. 95 and the gates were operational and flashing before the collision. Witnesses said the driver tried to slow down at the last minute but couldn't.

The National Transportation Safety Board dispatched a "go-team" to investigate the accident.

A passenger on board the train described to ABC News what happened.

The Amtrak train, which may have been traveling nearly 80 miles an hour, came barreling through the intersection.

"We were driving along on the train and apparently a truck decided that it was going to run the stop out in the middle of the desert -- nothing out here for miles," Jim Bickley told ABC News. "[It] hit the side of the Amtrak car. It was a coach car with people in it.

"My wife and I were in the fourth car, the observation car," he said. "We felt a jolt and a big ball of flames went by the left window with a bunch of black smoke. People yelled.

"There was a lot of smoke so we decided to stick our head out of one of the doors and saw the train on fire," Bickley said.

Two of the rail cars caught fire as passersby on the highway stopped to help.
Local and state police and rescue squads rushed to the scene. So did the miliary. A nearby naval air station sent helicopters to help evacuate the injuried.

There were approximately 204 passengers and 14 crew members aboard Train 5 of the westbound California Zephyr, according to Amtrak. The train was headed to Emeryville, Calif., from Chicago.

The accident at 11:20 a.m. PT shut down a section of U.S. 95 between Interstate 80 and Fallon, Nev.

"Amtrak managers and representatives of Union Pacific, the track owner, are enroute to the scene, along with emergency responders," Amtrak said in a written statement released at 1:15 p.m. PT on the company website. "We are saddened by any injury and appreciate the emergency response by local and state agencies."

Amtrak set up a phone number where friends and family of people aboard the train could seek information -- 800-523-9101.

Collisions at rail crossings are not uncommon. Safety groups estimate that a train in the U.S. collides with a person or vehicle nearly every three hours.

In 2010 there were more than 2,000 collisions between vehicles and trains at railroad crossings, according to Operation LifeSafer.